Fungi exs upsal. 21: 952. 1941.
Common Name: none
Synonyms: Peziza leucomelas Persoon; Paxina leucomelas (Persoon) Kuntze; Acetabula leucomelas (Persoon) Saccardo.
Ascocarp sessile to substipitate, 1.5-4.0 cm broad, urn-shaped to cupulate, in age the margin sometimes spreading and torn in a stellate pattern; hymenium dull grey-brown to blackish-brown, glabrous; external surface whitish at the base, dull grey to blackish-brown, above, pubescent with a hand-lens; stipe when present, very short, consisting of whitish folds or blunt ribs; context thin, brittle, approximately 1.0 mm thick, two-layered, watery-grey and whitish; odor and taste mild.
Spores 21.0-25.0 x 11.5-13.0 µm, elliptical, smooth, thin-walled, with a single oil droplet at maturity; asci tips inamyloid; spores inamyloid, white in deposit.
Solitary to scattered on soil among conifer needles; found in coastal and montane forests in the spring; fairly common but easily overlooked.
Helvella leucomelaena is recognized by a Peziza-like cup shape, the hymenium dull greyish-black to dark greyish-brown, the exterior greyish-black and white. The contrasting colors are the basis for the species name. Helvella queletii is similar but has a distinct, ribbed, white stipe that extends to the base of the cup, and an exterior that is lighter than the hymenium. Also cupulate, but less likely to be confused, is Helvella acetabulum, which is brown to ochre-brown, the ribs reaching from the base of the stipe to the cup margin.
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Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Kempton, P.E. & Wells, V.L. (1970). Studies on the Fleshy Fungi of Alaska. IV. A Preliminary Account of the Genus Helvella. Mycologia 62(5): 940-959.
Weber, N.S. (1972). The Genus Helvella in Michigan. Michigan Botanist 11: 147-201.
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